3D Printing for Production: We’re Missing this One Thing

It has been a few weeks since I attended the Additive Manufacturing Users’ Group conference (AKA “AMUG”), and I have been thinking about 3D printing for production quite a bit. A lot of the presentations and conversations at the event talked about mass production with 3D printing. However, my conclusion is that we are still years away from 3d printing for production becoming reality.

Production with 3D printing is possible today in some industries – like aerospace.

Adoption of 3D printing for production faces many
challenges. 3D printing companies tend to focus on the technical aspects of 3D
printing – mainly print speed – to try to help adoption. However, the bigger
challenge lies in engineering standards.

While it is way more exciting to discuss the latest
technologies trying to make mass production with 3D printing come to fruition,
engineering standards are a serious challenge that needs to be addressed. But
why are engineering standards important in the first place? And why is it so
hard to create them for 3D printed parts?

Engineering standards create a common language and quality
assurance for companies working together. They allow one business to buy parts
from another, with clear expectations set around all sorts of characteristics:
part tolerance, surface finish, and metallurgy quality, just to name a few. By
making parts to a set quality standard, the world gets safer parts and
products. When applied to 3D printing, establishing these standards gets
complicated.

3 Challenges facing Mass Production with 3D Printing

1. Anisotropy

This is an engineering term for “non-uniformly strong”. An isotropic part is one that has the same strength and stiffness characteristics no matter what angle you apply force from. Still with me? A 3D printed part is anisotropic by nature, because of the layer-by-layer process that creates it.

In traditional manufacturing, a block of metal or plastic is
consistent throughout the entire stock material. This creates uniform strength
properties that are easy to simulate and predict how the parts will behave
under stress.

2. Technology Variations

“We need standards for 3D printed parts”, is an easy
statement to throw out there. Digging deeper, it is a massive challenge because
of how many different types of 3D printing, different materials, and different
quality of parts even within the same technology type. These challenges are
simpler in conventional subtractive manufacturing, because the stock material
has had standards for many years.

Fused Deposition Modeling (FDM/FFF), Stereolithography (SLA), Selective Laser Sintering (SLS), and material jetting (PolyJet) all have different part properties and use different materials. Creating a standard for parts with such a broad range of technologies and materials is a massive undertaking that will take time to establish – and a crazy amount of material test coupons.

3. Process Variations

When cutting standard, off-the-shelf materials, it is easy
to tell if something goes wrong. The material has uniform consistency
throughout, so if there are any issues with the part, they are visible on the
surface. 3D printing almost always has a different interior consistency
(infill) than its outside shell.

Let’s say your part has three outer shells. If the 3D
printer fails to extrude properly on the inside shell, how would you know? If
you use 3D printing for production, and a part on a car fails due to an unseen
defect, it could have serious consequences. Establishing an engineering
standard for 3D printed parts can help prevent such problems before they begin.

The inside of 3D printed parts can be difficult to inspect.

Is Additive Manufacturing Ready for Mass Production?

I believe mass production with 3D printing will eventually
be more popular than conventional (subtractive) manufacturing processes. To
clarify, by “eventually”, I mean the technology still has a number of
challenges before 3D printing for production is widely adopted. The biggest
challenge is establishing a quality standard for 3D printed parts. It will take
time – years – for the various engineering organizations like ISO and ASTM to
create these standards, but once they do, I am excited to see 3D printing used
by companies everywhere for end-use parts.